Metal-spraying process.



R. W. E. MOORE.

METAL SPRAYING PROCESS. mucmou FILED 1111.13. 1911,

1,164,008. Patented Dec.14,1915.

WITNESSES? $7 QNVENTOR 1 ATTORNEY an sraaas PATEN I;

RALPH W. E. MOORE, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR EIIEO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION 015 PENNSYLVANIA.

METAL-SPRAYING PROCESS.

maac ca.

Specification of Letters Patent.

Patented Dec. 14L, jmtfi.

Application filed March 18, 1911. Serial No. 614=,250.

. vented a new .and useful Improvement in MetaLSpraying Process, of which the following is a specification.

My invention relates to processes and apparatus for producing metal coatlngs or films, and it has special reference to the production of such coatings by means of a spraying rocess.

Ihe ob ect of my invention is to provide a simple and commercial process whereby coatings of the above-indicated character may be effectively and cheaply applied either to metallic or non-metallic bodies.

In recent years, there has been an increasing demand'for a commercial and economical method of coating various bodies with thin metallic films for protection against weather conditions and acid fumes, for soldering and ornamental purposes, and for purposes of electrical conductivity.

According to my present invention, I produce thin coatings of metal by mechanically sub-dividing and disintegrating the metal in a molten state, and projecting the disassociated particles at a high velocity upon the bodies to be coated, by means of a spraying process.

Although various mechanical methods may be employed for breaking-up and atomizing the molten metal, I shall set forth in detail only the process and means which I consider preferable from a commercial stand-point and which produces superior results.

The success. of a process for spraying metals depends upon the degree of subdivision and disassociation of the metal, and upon the velocity with which itis projected upon the body to be coated. In order to obtain a sub-division of the highest degree, I

. have devised a peculiar type of spraying device or nozzle for splitting up the molten metal into minute particles which substantially constitute a mlst or vapor.

By means of my nozzle, an exceedingly thin film of molten metal is forced, under pressure, out of an outer containing vessel and is acted. upon by a rapidly expanding and diverging jet of air or gas which is compressed and heated to a high degree. The et of air or gas is delivered rom a centrally disposed orifice which is sodesigned and located with respect to the outer portlon of the nozzle that the thin annular film 1s pro ected at a high velocity against the sldes of an annular bafile-plate or deflecting surface, where it impinges with such force that it is broken up into a mist of minute.

particles. This mist is then projected at a high velocity against the body to be coated, and the impingement thereon causes the individual particles to flatten out and reassociate themselves into a thin, integral and homogeneous film.

I have found by experiment that it is unnecessary to pro-heat the bodies to be coated and that cloth, wood and paper may be treated as readily as metallic bodies, which demonstrates the fact that the mist or spray is of comparatively low temperature at the instant of impingement. It is, therefore, evident that the success of my process depends upon the degree of disintegration and the velocity with which the particles are projected against the body to be coated.

I do not wish to be restricted to the specific means or mode of operation herein described, as 'various devices and methods may be employed which embody the principle of my invention and which secure the benefits thereof to a greater or less degree.

My invention may be best understood by reference to the single figure of the accompanying drawing, which is a diagrammatic view of suitable apparatus for practising my invention, a portion thereof being shown on an. enlarged scale and in cross section.

Referring to the drawing in detail, the apparatus here shown comprises a tank or reservoir 1 adapted to contain air or gas under compression, a heater 2 for raising the temperature of said air or gas, a spraying device or nozzle 3 adapted to contain a body of molten metal 4 and to discharge it in the form of a spray upon a body 5 to be coated, a heater 6 to maintain the metal 4 in a molten state, and suitable piping and fittings for practising my invention.

The tank or reservoir 1 and the heater 2 may be of any well-known construction, and

v10ft are only illustrative of any suitable devices rounds the lower ortion of the spraying device 3, although 1t is not restricted to any particular construction or location.

The spraying device 3 comprises anouter cylindrical member 7 which is provided with an upper cap portion 8 and a lower cap portion 9, a centrally disposed pipe 10,

the upper end of .which is adjustably supported in the cap portion 8 by means of an adjustable bushing 11 and the lower portion of which is maintained in position by means efiected, the degree of which depends upon' the difi'erence in pitch of the threads hereinbefore mentioned. Thus, a ready and fine adjustment may be secured, as will be readily understood.

The lower cap portion 9 is provided with a a centrally disposed circular opening 15, the

lower walls of which are substantially vertical while the upper walls are beveled to form an inclined surface 16 which constitutes a seat for the lower extremity of the pipe 10. The vertical walls of the openin 15 constitute an annular bafie-plate or de ecting sur-- face for a purpose to be hereinafter set forth.

In order to obtain a diverging stream of air or gas, an internally tapered bushing 17 is disposed within the lower end of the pipe 10 to form a contracted orifice which is adapted to produce the desired results. An elbow 18, having a removable cap 19, is provided in the side of the outer member 7 for the purpose of introducing metal, and a pipe 20 is also provided and connected to the reservoir 1 in order to maintain a high pressure upon the molten metal 4:. In some instances, it is found unnecessary to employ additional pressure, but, in general, superiorresults are I obtained by its use.

Assuming the various parts of the apparatus to occupy the positions shown, the mode of procedure and the operation are as follows: The reservoir 1 is first filled with air or gas under pressure, after which the heatdownwardly through the discharge opening tracted' orifice formed by the bushin 15. Valve 23 is then opened, thereby causing the air or gas under pressure to be dlscharged at a high velocity through the con:- 1

The shape and location of the bushing 1 are such that the discharged air or gas is' caused to expand and diverge rapidly, whereby it acts upon the thin annular film of molten metal in such manner as to project it at a high velocity against the vertical walls of the opening 15 which constitute a baflleplate. Here the impact is suficient to break up the film of molten metal into minute particles, which are further projected at a high velocity upon the body 5 to be coated.

By suitably adjusting the various parts of the spraylng device 3, the properties of the mist may be so controlled that the impingement thereof upon the body to be coated causes the individual particles to flatten out and form themselves into a homogeneous and integral coating or film.

Variations in the mode of procedure hereinbefore set forth may be efi'ected without departing from the spirit and scope of my invention, and such igariations are intended to be covered by the appended claims.

I claim as my invention:

1. The method of producing a metallic coating which consists in mechanically subdividing molten metal into minute particles by impingement against a heated deflecting surface, and causing said particles to be projected at high velocity upon the body to be coated.

2. The method of producing a metallic coating which consists in projecting a stream of air or gas at a high velocity into contact with a stream of molten metal, whereby said metal is caused to impinge against a heated deflecting surface and is sub-divided into fine particles which are projected upon the body to be coated.

3. The method of producing a metallic coating which consists in producing a thin annular film of molten metal, projecting a jet of compressed air or gas at a high velocity outwardly against said film, whereby said metal is finely sub-divided, and causing said sub-divided metal to impinge upon the surface of the body to be coated.

4. The method of producing a metallic coating which consists in projecting a fine jet of molten metal against a heated surface at great velocity, whereby said jet of metal I is disassociated into minute particles, and causing said particles to impinge with great velocity upon the surface of the body to be coated.

5. The method of producing a metallic coating which consists in producing a thin annular film of molten metal, projecting a jet of pre-heated air or gas outwardly against said film of metal, whereby said film 1,1e4,ooe we is caused to impinge at a high velocity and subscribed my name this 1st day of March at an inclined angle against a heated surface 1911. to sub-divide said metal into fine particles,

and finally projecting said particles at a RALPH MOURE' 5 high velocity upon the surface of the body Witnesses:

to becoated. B. B. Hmns In testimony whereof, I have hereunto M. CLARA 

